Giz is a big fan of the secret passageway, but this sub-staircase version really is the mutt's nuts. A cross between a drawbridge, a private jet and something that, to kids, is straight out of Indiana Jones and the Duplex of Suburbia, the concealed hidey-hole is just one of a series of designs from Creative Home Engineering, a firm that puts hidden doors just about everywhere you wouldn't think of looking. Prices range from $5,000 to a cool quarter of a million. [Creative Home Engineering via BallerHouse]